MAUDE Adverse Event Report: ROCHE DIAGNOSTICS ELECSYS TACROLIMUS; TACROLIMUS IMMUNOASSAY

Catalog Number	07251254190
Medical Device Problem Code	Low Test Results (2458)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	08/21/2025
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
The cobas e 801 analytical unit serial number is (b)(6).The customer reported that the qc is passing.The investigation is ongoing.
Event or Problem Description
There was an allegation of questionable elecsys tacrolimus results from the cobas e 801 analytical unit for two patients.Patient 1's initial result collected from a medication line that the patient receives parenteral nutrition was 32.5 ng/ml with a mass spectrometry analyzer.The result with the e801 was 23 ng/ml.A second result after a dilution of 1:2 was 11.7 ng/ml.Another sample was collected from the dialysis catheter with the following results.The result with a mass spectrometry analyzer was 5.8 ng/ml.The result with the e801 was 6.23 ng/ml.On (b)(6) 2025, a sample was collected from the dialysis catheter.The result with a mass spectrometry analyzer was 6.7 ng/ml.The result with the e801 was 6.14 ng/ml.On (b)(6) 2025, a sample was collected from the medication line without parenteral nutrition.The result with a mass spectrometry analyzer was 23.9 ng/ml.The result with the e801 was 16.3 ng/ml.Patient 2's initial result with a mass spectrometry analyzer was 3.4 ng/ml.The result with the e801 was 4.65 ng/ml.
Additional Manufacturer Narrative
Medwatch field d device identification section d4 lot no was updated.The customer clarified that the information provided for patient 2 is a parallel control sample.Additional results were provided for patient 1.The analyzer used for the results was not provided.On (b)(6) 2025, a sample drawn from the femoral vein had a result of 7.7 ng/ml.The patient was reported to be in icu during this time.On (b)(6) 2025, a sample drawn from the line used for medication and parenteral nutrition had a result of 27.9 ng/ml.On (b)(6) 2025, the result from a new sample from the line used for medication and parenteral nutrition was 28.5 ng/ml.On (b)(6) 2025, the result from a new sample from the line used for medication and parenteral nutrition was 41.5 ng/ml.On (b)(6) 2025 a sample was drawn from the femoral vein and analyzed by elecsys tacrolimus with a result of 6.1 ng/ml.The sample was repeated on (b)(6) 2025 with the mass spectrometry analyzer, with a result of 6.4 ng/ml.It was asked, but not specified whether this sample is from either of the already reported patients.The investigation determined that the sample drawn from the central line was not adequate.Also, the difference between the elecsys tacrolimus and the assay used with the mass spectrometry analyzer is the sample from the central line as well.No additional root cause was found.

• Brand Name: ELECSYS TACROLIMUS
• Common Device Name: TACROLIMUS IMMUNOASSAY
• Manufacturer (Section D): ROCHE DIAGNOSTICS; 9115 hague road; indianapolis IN 46250 0457
• Manufacturer (Section G): ROCHE DIAGNOSTICS GMBH; sandhofer strasse 116; mannheim (baden-wurttemberg) 68305 ; GM 68305
• Manufacturer Contact: natalie catton ; 9115 hague road; indianapolis, IN 46250
• MDR Report Key: 23778185
• Report Number: 1823260-2025-05052
• Device Sequence Number: 18668307
• Product Code: MLM
• UDI-Device Identifier: 04015630940271
• UDI-Public: 04015630940271
• Combination Product (Y/N): N
• Initial Reporter Country: SP
• PMA/510(K) Number: K173857
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Foreign,Health Professional,User Facility
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 01/08/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Operator of Device: Health Professional
• Device Catalogue Number: 07251254190
• Device Lot Number: 834814
• Was Device Available for Evaluation?: Yes
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Follow-Up
• Initial Date Received by Manufacturer: 11/20/2025
• Supplement Date Received by Manufacturer: 12/15/2025
• Initial Report FDA Received Date: 12/11/2025
• Supplement Report FDA Received Date: 01/08/2026
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Is the Device Labeled for Single Use? (Y/N): No
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1
• Patient Sex: Unknown